Bitcoin's next protocol upgrade may not arrive until 2028 or later, according to developers surveyed at a recent industry conference. The leading candidate proposal would fix four long-known bugs in the network's consensus rules and does not add a new feature, making it a maintenance-focused upgrade rather than a feature release.

The proposal is called the Great Consensus Cleanup, or BIP-54 — short for Bitcoin Improvement Proposal 54, the numbered format developers use to propose changes to Bitcoin's protocol. It was first put forward in 2019 and targets flaws in Bitcoin's consensus rules that have been around for years.

Longtime Bitcoin developer Matt Corallo, a co-author of BIP-54, says there is an 80% chance it becomes the network's next soft fork. He shared the estimate during an appearance on MARA Foundation TV with Isabel Foxen Duke, head of the MARA Foundation.

"There's a laundry list of things we know of that we really need to clean up," Corallo said. He added that the issues are real concerns but "not like, 'Oh, the sky is falling.'"

Four Bugs on the Fix List

The first target is poison blocks. Under this scenario, a miner could craft a specially constructed block that exploits performance bottlenecks in the software, which would slow down validation for other nodes on the network and give that miner a short-term advantage.

The second is the time warp bug. A loophole in Bitcoin's two-week difficulty adjustment window would let miners controlling a majority of the network's hashrate manipulate block timestamps, which speeds up how quickly new blocks are issued.

The third is Merkle malleability. Because a 64-byte transaction is the same size as an internal Merkle tree node, an attacker could in theory forge Merkle proofs that trick light clients into accepting fake transactions as legitimate.

The fourth involves duplicate coinbase transactions. Old design quirks in the protocol allowed duplicate transaction IDs, and these will resurface at future block heights. That could overwrite existing coins or disrupt ledger accounting.

Corallo said BIP-54 "fixes some stuff that everyone agrees are problems." None of the four issues is considered urgent, but each is a recognized weakness in the network's design. And because those flaws are embedded in the consensus rules themselves, they cannot be patched the way ordinary software can — fixing them requires a soft fork, a backward-compatible change to the network's validation rules that needs ecosystem-wide agreement to activate.

A Test Run for Activation

Corallo also sees BIP-54 as practice. Many current Bitcoin developers have never worked through a soft fork, and the last one, Taproot, activated in 2021. Taproot's rollout came after months of debate over how it should be activated, with arguments pitting miner signaling thresholds against mandatory user flag days.

"In every recent soft fork, there's also been a bunch of drama about activation mechanisms," Corallo said. He hopes the community can settle that process once, then "copy and paste and reuse it" for future upgrades.

Since Taproot, other proposed changes have stalled. Upgrades such as OP_CAT (BIP-347) and OP_CHECKTEMPLATEVERIFY (BIP-119) have struggled to reach ecosystem-wide consensus, and the disagreements have often been framed as a debate over "ossification," or whether Bitcoin's core protocol should continue to change.

Corallo said soft forks have always involved technical hurdles. More recently, however, he has observed that political and social friction within the community has become just as relevant to whether an upgrade moves forward.

Not everyone is enthusiastic about the plan. Paul Sztorc, co-founder and CEO of LayerTwo Labs, wrote on X that BIP-54's potential activation is "kind of depressing, since it is a janitorial maintenance fork that doesn't do anything."

In a post shared on X, Sztorc listed the activation-date predictions he gathered from conference attendees:

Yesterday, the TabConf Elite weighed in on SFD, the date of Bitcoin's next soft fork activation. (This is the Bitcoin version of P(doom).) These were the reports, of the best and brightest: Sept 1, 2027 Dec 31, 2027 Feb 17, 2028 Mar 1, 2028 June 15, 2028 Dec 31, 2028 Dec 31,…

— Paul Sztorc (@Truthcoin) (October 13, 2026)

Sztorc also surveyed developers at TABconf, held in Atlanta. According to him, most expect the Great Consensus Cleanup to be the next soft fork, with the earliest estimate for activation in September 2027 and most respondents pointing to 2028 or later.

Those dates are estimates, not commitments. No activation mechanism has been chosen for BIP-54 yet, and settling on one is the step that has generated drama in every recent soft fork. Until that hurdle is cleared, the timing of the next upgrade remains an open question.